"Forbidden" transitions between quantum Hall and insulating phases in p-SiGe heterostructures

Abstract

We show that in dilute metallic p-SiGe heterostructures, magnetic field can cause multiple quantum Hall-insulator-quantum Hall transitions. The insulating states are observed between quantum Hall states with filling factors ν=1 and 2 and, for the first time, between ν=2 and 3 and between ν=4 and 6. The latter are in contradiction with the original global phase diagram for the quantum Hall effect. We suggest that the application of a (perpendicular) magnetic field induces insulating behavior in metallic p-SiGe heterostructures in the same way as in Si MOSFETs. This insulator is then in competition with, and interrupted by, integer quantum Hall states leading to the multiple re-entrant transitions. The phase diagram which accounts for these transition is similar to that previously obtained in Si MOSFETs thus confirming its universal character.

References in corpus (7)

• Metallic behavior and related phenomena in two dimensions
• Metal Insulator transition at B=0 in p-SiGe
• Global phase diagram for the quantum Hall effect: An experimental picture
• Collapse of Spin-Splitting in the Quantum Hall Effect
• Phase diagram of the integer quantum Hall effect in p-type Germanium
• Phase Diagram of Integer Quantum Hall Effect
• Universal Behaviour of Metal-Insulator Transitions in the p-SiGe System

Cited by in corpus (7)

• Metal-insulator transitions and the effects of electron-electron interactions in two-dimensional electron systems
• On the low-field insulator-quantum Hall conductor transitions
• Vertical Confinement and Evolution of Reentrant Insulating Transition in the Fractional Quantum Hall Regime
• Magnetoresistivity and Acoustoelectronic Effects in a Tilted Magnetic Field in $p$-Si/SiGe/Si Structures with an Anisotropic $g$ Factor
• Global quantum Hall phase diagram from visibility diagrams
• Magnetoresistance in Dilute $p$-Si/SiGe in Parallel and Tilted Magnetic Fields
• Magnetoresistivity in a Tilted Magnetic Field in p-Si/SiGe/Si Heterostructures with an Anisotropic g-Factor: Part II